Condition Assessment of Water Supply Infrastructure

A capacity-weighted reliability surface is suggested as a tool to assess the condition of deteriorating water supply infrastructure. A method is developed for calculating the spatial variation in reliability throughout a water distribution network. The method considers the reliability to meet demands at nodes to depend on the reliability and hydraulic capacity of all the network elements leading from the sources. Using a measure of network connectivity, point values of the reliability of water supply at demand nodes are calculated. An efficient algorithm is developed to adjust these point values in order to account for the carrying capacities of the components linking the source of water to the demand points. The adjusted values are then contoured to define the reliability surface. The surface may be used as an aid for prioritizing the maintenance and rehabilitation of the water distribution network.